Phytochemical and In Vitro Antibacterial Assessment of Selected Wild Edible Plants From Southwestern Ethiopia.

BACKGROUND

Wild edible plants (WEPs) are vital for food security and traditional medicine, particularly in resource-limited areas. Despite their potential, their use is constrained by a lack of scientific evidence. This study assesses the phytochemical properties and antibacterial activity of chosen WEPs from southwestern Ethiopia.

METHOD: Observational and experimental study designs were utilized to identify and select WEPs through focus group discussions, key informant interviews, and multicriteria decision analysis. WEP samples were collected, dried, powdered, and extracted separately using methanol, ethanol, and acetone solvents. Physicochemical and qualitative phytochemical screenings were evaluated following standardized procedures. Antibacterial activity was evaluated using agar disk diffusion and broth dilution methods against Staphylococcus aureus and Escherichia coli, with concentrations varying from 10 to 100 mg/mL. Gentamicin served as a positive control, whereas 2% dimethyl sulfoxide (DMSO) acted as a negative control. Data analysis was performed using Microsoft Excel 2010 and R software (Version 4.5.2). A three-way ANOVA analyzed the effects of solvent type, bacterial species, and extract concentration; Tukey's HSD for post hoc was applied for comparisons at α = 0.05 to denote statistically significant differences.

RESULTS

Among 22 medicinally important WEPs, Mussaenda arcuata and Pteridium aquilinum were selected for experimentation. M. arcuata exhibited higher water and ethanol extractive values (p < 0.001). Alkaloids, glycosides, tannins, flavonoids, saponins, steroids, phenols, terpenoids, quinones, protein, amino acids, and lipids or oils were observed phytochemical compounds, with the exception that P. aquilinum lacked reducing sugars. The acetone extract of M. arcuata demonstrated significant antibacterial activity against S. aureus at 100 mg/mL, with a zone of inhibition of 17.2 ± 0.11 mm (p < 0.05), surpassing the ethanol extract's 16.2 ± 0.07 mm. Both ethanol and acetone extracts effectively inhibited the growth of S. aureus and E. coli, establishing a minimum inhibitory concentration of 25 mg/mL.

CONCLUSION

The extracts of M. arcuata exhibited a dose-dependent antibacterial activity against both S. aureus and E. coli bacteria, with the acetone extract proving more potent than the ethanol extract. M. arcuata is recommended for further research on its active compounds and safety for potential antimicrobial development, whereas P. aquilinum showed no significant antibacterial activity despite the presence of bioactive compounds.